Iontophoresis

3. IONTOPHORESIS
Prepared by Mohmmad Rasool Sakhawarz.

4. CONTENTSCONTENTS
INTRODUCTION
PRINCIPLES OF IONTOPHORESIS
Advantages
Problems by Iontophoresis
Iontophoresis Diagram
Mechanisms Of Drug delivery
And etc…

5. Introduction

IontophoresisIontophoresis is a non-invasive method of propelling is a non-invasive method of propelling
high concentrations of a charged substance, normallyhigh concentrations of a charged substance, normally
medication or bioactive agents, transdermally by medication or bioactive agents, transdermally by
repulsive electromotive force using a small electrical repulsive electromotive force using a small electrical
charge approximately (0.5 Am/cmcharge approximately (0.5 Am/cm
22
) applied to an ) applied to an
iontophoretic chamber containing a similarly charged iontophoretic chamber containing a similarly charged
active agent and its vehicle.active agent and its vehicle.
•It is a Painless, Sterile, Noninvasive Technique
•Iontophoresis is well classified for use in transdermal drug
delivery.

6. Advantages of Iontophoresis
• Virtually painless when properly applied.
• Provides option for patients unable to receive injections.

• Reduced risk of infection due to non-invasive nature.
•Medications delivered directly to the treatment site.

• Minimizes potential for tissue trauma from an injection.

• Treatments are completed in minutes.

7.  problems by iontophoresis
•An excessive current density usually results in pain.
•Burns are caused by electrolyte changes within the
tissues.
•The high current density and time of application would
generate extreme pH, resulting in a chemical burn.
• This change in pH may cause the sweat duct plugging
perhaps precipitate protein in the ducts.
•Electric shocks may cause by high current density at the
skin surface.
• Ionic form of drug in sufficient concentration is
necessary for iontophoretic delivery.

8. Principles of Iontophoresis
•Electrode placement is dependent on the electric charge of the
ion which you are trying to deliver into the tissue.
•A positive ion will be delivered from the positive electrode
and a negative ion will be delivered by the negative electrode.

•Electrical energy assists the movement of ions across the
stratum corneum according to the basic electrical principle
“like charges repel each other and opposite charges attract “like charges repel each other and opposite charges attract
each other.”each other.”

9. Iontophoresis Diagram
A)
B)
B)

10. How Does it work?

11. Iontophoresis enhances transdermal drug
delivery by three mechanisms
(a) ion-electric field interaction provides an additional force
that drives ions through the skin.
(b) the flow of electric current increases the permeability of
the skin.

(c) electro-osmosis produces bulk motion of solvent that
carries ions or neutral species with the solvent stream.
Electro-osmotic flow occurs in a variety of membranes and
is in the same direction as the flow of counter-ions. It may
assist or hinder drug transport.

12. Components needed for effective iontophoresis
delivery
•Power source for generating controlled direct current.
•Electrodes that contain and disperse the drug.
•Negatively or positively charged aqueous medication of relatively small molecule
size (<8000 Daltons).
•Localized treatment site.

13. PHARMACOKINETICS OF ION TRANSFER
•Transdermal iontophoresis delivers medication at a constant rate
so that the effective plasma concentration remains within a
therapeutic window for an extended period of time.
¨Therapeutic window - the plasma concentrations of a drug
which should fall between a minimum concentration
necessary for a therapeutic effect and the maximum
effective concentration above which adverse effects may
possibly occur.

14. Movement of Ions In Tissue
Higher current intensities necessary to create ion movement in
areas where skin and fat layers are thick, further increasing
chance of burns around negative electrode.
Sweat ducts are primary paths by which ions move through
the skin.
Once the ions pass through skin they recombine with existing
ions and free radicals in the blood thus forming the necessary
new compounds for favorable therapeutic interactions.

16. Iontophoresis Generators
¨Produce continuous
direct
current.
¨Assures unidirectional
flow
of ions.